1. Field of the Invention
The present invention relates generally to a light emitting diode lamp, and particularly to a heat dissipation device of the lamp.
2. Description of Related Art
In recent years, light emitting diodes (LEDs), because of being highly efficient light sources, have come to be widely used in such fields as automotive transport, display screens, and traffic control indicators.
It is well known that LEDs emit light within a relatively narrow-band spectrum. Therefore, LEDs are inherently suited as sources of colored light, whereas many applications require white light with a broad spectrum. Two basic approaches for producing white light rely on either partial or complete conversion of short-wave radiation from LED chips or using a variety of independently controlled primary colored LEDs. During operation, when the variety of colored LEDs give off light, heat is also produced, and thus the working temperature of the LEDs increases. However, rates of change of the luminous intensity of the variety of colored LEDs relative to their respective working temperature are much different from each other. For example, the luminous intensity of the red LEDs, the yellow LEDs or the orange LEDs decreases much more than that of the blue LEDs for equal increases in working temperature. Color, luminance, and color temperature of the white light thus are much affected by change of the red LEDs. Therefore a heat dissipation device is needed to keep the variety of colored LEDs working at different suitable working temperatures.
Therefore, a heat dissipation device for the LED lamp is desired to overcome the above describe shortcomings.